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By Cameron Glenn

The Islamic State emerged with breathtaking speed in 2014 after seizing large swaths of Iraq and Syria. It has since overtaken al Qaeda as the dominant worldwide jihadist organization. ISIS has since achieved what had been al Qaeda’s longtime goal – establishing a global caliphate with its own government, economy and army. The following is an overview of the origins, structure, leadership, and ideology of ISIS.


The ISIS experiment in blending Islam and politics remains in its infancy. The movement emerged from the remnants of al Qaeda in Iraq (AQI), founded in 2004 by Abu Musab al Zarqawi. It was rebranded as the Islamic State in Iraq in 2006. The surge of U.S. troops in Iraq in 2007 drove the group from its strongholds; many of its core members were killed or imprisoned.  

The group faded into obscurity for several years. But in 2011, it began to reemerge as Iraq’s Shiite-dominated government fueled discontent among Sunnis. It also took advantage of the growing unrest in Syria by dispatching fighters to Idlib, Aleppo, and Deir Ezzor. In July 2012, it launched its “breaking the walls” campaign to free former AQI militants through prison breaks.

The group changed its name to the Islamic State of Iraq and Syria (ISIS) in 2013 and seized Fallujah and Ramadi in Iraq. By January 2014, the group had seized several smaller cities in Syria and established a de facto capital in Raqqa.

In June 2014, ISIS launched an offensive that seized large swaths of territory across northern Syria and Iraq. ISIS leader Abu Bakr al Baghdadi declared a caliphate stretching from Aleppo in Syria to Diyala in Iraq, rebranding the group the Islamic State. ISIS established a basic bureaucracy in its territories, with institutions based on its hardline interpretation of Islam.

The Caliphate

The ISIS "caliphate" practices a rigid Salafi interpretation of Sharia. It has no constitution. No country recognizes its borders, which include about one third of both Syria and Iraq. It has vowed to fight any state or group that does not share its rigid worldview. It is a member of no international organizations. It persecutes all other faiths and forces conversion. Its economy relies on smuggling oil, extortion, kidnapping and financial aid from Salafi supporters in the Arab world.


The first issue of ISIS’s “Dabiq” magazine, published in July 2014, attempted to justify the caliphate. The magazine listed a five-step process that focuses on migrating to a weak state, recruiting members, and fomenting local chaos. It claims that “this has always been the roadmap towards Khilafah (caliphate)” and criticizes “other famous jihad groups” – presumably al Qaeda – who do not attempt to capture and rule territory. 

ISIS leaders describe the caliphate as a utopian Islamic society encompassing Muslims of all ethnicities. The influx of foreign fighters to the Islamic State seems to reflect this global orientation, as more than 20,000 militants from more than 80 countries have reportedly flocked to Syria. But reports suggest that life in the Islamic State is not as idyllic as its leaders claim. Foreign fighters occupy many of the top administrative posts in the bureaucracy, generating resentment among Syrians. ISIS fighters also reportedly benefit disproportionately from the collection of taxes, receiving generous salaries and benefits from tax revenues without being required to contribute to them.

In their own words

“By Allah’s grace – you have a state and Khilafah, which will return your dignity, might, rights, and leadership. It is a state where the Arab and non-Arab, the white man and black man, the easterner and westerner are all brothers. It is a Khilafah that gathered the Caucasian, Indian, Chinese, Shami, Iraqi, Yemeni, Egyptian, Maghribi (North African), American, French, German, and Australian. Allah brought their hearts together, and thus, they became brothers by His grace, loving each other for the sake of Allah, standing in a single trench, defending and guarding each other, and sacrificing themselves for one another. Their blood mixed and became one, under a single flag and goal, in one pavilion, enjoying this blessing, the blessing of faithful brotherhood.”  - Speech by ISIS leader Abu Bakr al Baghdadi

“These phases [of establishing a caliphate] consist of immigrating to a land with a weak central authority to use as a base where a jama’ah can form, recruit members, and train them...The jama’ah would then take advantage of the situation by increasing the chaos…The next step would be to fill the vacuum by managing the state of affairs to the point of developing into a full-fledged state, and continuing expansion into territory...This has always been the roadmap towards Khilafah (caliphate) for the mujahidin.” 

“Sadly, [the mujahidin] are now opposed by the present leadership of famous jihad groups who have become frozen in the phase of nikayah (injury) attacks, almost considering the attainment of power to be taboo or destructive.”– Issue #1 of ISIS’s “Dabiq” magazineJuly 2014

Global Reach 

Islamic State leader Abu Bakr al Baghdadi has vowed that Muslims around the world should be united “under a single flag and goal.” ISIS is aggressively trying to conquer territory. It has called on Muslims worldwide to either immigrate to the Islamic State or pledge allegiance to it. ISIS membership has grown rapidly since 2011, and in late 2014 the Central Intelligence Agency believed that ISIS had up to 31,500 fighters. U.S. officials estimated in 2014 that around 15,000 of them were foreign fighters. By September 2015, the figure had increased to 25,000. Around 250 of them were Americans.

Source: House Homeland Security Committee

A handful of jihadist groups around the world began aligning with ISIS after it declared its caliphate. By mid-2015, more than 30 jihadist groups had either pledged allegiance to ISIS or declared support for it. These groups included:  

  • Sinai Province (formerly Ansar Beit al Maqdis), based in Egypt’s Sinai peninsula 
  • The Shura Council of Islamic Youth, based in eastern Libya 
  • Jund al Khilafah, a splinter group from al Qaeda in the Islamic Maghreb (AQIM) based in Algeria 
  • Khorasan Province, based in Afghanistan and Pakistan under the leadership of former Taliban commander Hafiz Said Khan 
  • Boko Haram, based in Nigeria, with around 9,000 fighters 
  • Sanaa Province, based in Yemen 
  • Hijaz Provinceand Najd Province, based in Saudi Arabia

Smaller groups in Jordan, the Caucuses, Indonesia, the Philippines, and Nigeria have also expressed support for ISIS, but Baghdadi has not declared all of them formal ISIS provinces. Some groups, like Boko Haram and Ansar Beit al Maqdis, are known to have collaborated with al Qaeda in the past, before aligning with ISIS. The affiliations are not always straightforward. Some members of al Qaeda in the Arabian Peninsula (AQAP) – one of al Qaeda’s strongest branches – have expressed support for ISIS.  

In their own words

“The Islamic State is facing a growing list of enemies, and it further underscores the fact that the lines are being drawn and the camps of īmān (believers) and kufr (non-believers) are both being cleansed. This will eventually lead to a camp of kufr with no trace of īmān, and a camp of īmān with no trace of hypocrisy, as per the statement of the Prophet...all parties will soon be forced to make a choice between the two.” - Issue # 4 of ISIS's "Dabiq" magazine

“With this declaration of the caliphate, it is incumbent upon all Muslims to pledge allegiance to the Caliph Ibrahim and support him…The legality of all emirates, groups, states, and organizations becomes null by the expansion of the caliph’s authority and arrival of its troops to their areas.” - Spokesman Shaykh Abu Muhammad al-Adnani al-Shami, "This is the Promise of Allah"

“If you cannot perform hijrah for whatever extraordinary reason, then try in your location to organize bay’āt (pledges of allegiance) to the Khalīfah Ibrāhīm. Publicize them as much as possible.” - Issue # 2 of ISIS's "Dabiq" magazine


ISIS draws on the same schools of thought as al Qaeda. Both are inspired by the works of medieval scholar Ibn Taymiyya, 20th century Egyptian ideologue Sayyid Qutb, and later scholars, such as Abu Muhammad al Maqdisi, a Palestinian-Jordanian who taught former al Qaeda in Iraq leader Abu Musab al Zarqawi. Both groups claim their hardline interpretations are reviving the purity of the faith when it was founded in the seventh century. But most influential jihadist ideologues, including Maqdisi, have remained loyal to al Qaeda. 

ISIS has tried to cultivate its own scholarly resources to boost its profile. ISIS scholars tend to be younger than those loyal to al Qaeda. The 30-year-old Bahraini Turki al Bin’ali is among ISIS’s most prominent scholars. In 2013, he wrote a biography of Baghdadi that claimed Baghdadi was a descendent of the Prophet Mohammed. 

Relationship with al Qaeda

ISIS and al Qaeda are rivals, despite their early links and ideological similarities. For more than two decades, al Qaeda was the dominant worldwide jihadist organization. But in 2014, ISIS quickly achieved what had been al Qaeda’s longtime goal – establishing a global caliphate. Tensions between the two groups played out on the battlefield in Syria. In 2013, ISIS began battling the Nusra Front – al Qaeda’s affiliate in Syria – for dominance. By March 2014, over 3,000 fighters had been killed in battles between ISIS and the Nusra Front. 

ISIS leaders repeatedly ignored commands and authority from al Qaeda’s core leadership. In February 2014, al Qaeda leader Zawahiri officially severed ties with ISIS. “ISIS isn’t a branch of al Qaeda and we have no organizational relationship with it,” Zawahiri said. “Nor is al Qaeda responsible for its actions and behavior.”

Although the two groups reportedly considered joining forces in late 2014, Nusra leader Abu Mohammed al Julani emphasized in 2015 that the groups remained at odds with no immediate plans to reconcile. In a recording released in September 2015, Zawahiri reiterated that he considered the ISIS caliphate illegitimate. But he also called for cooperation between al Qaeda and ISIS "to push back the attack of the enemies of Islam."

ISIS has conducted brutal sectarian attacks and, unlike al Qaeda, actively seeks to conquer and rule territory.  A 2014 ISIS publication claimed the group is “now opposed by the present leadership of famous jihad groups who have become frozen in the [attack] phase…considering the attainment of power to be taboo or destructive.”


The Caliph

 Abu Bakr al-Baghdadi
ISIS leader Abu Bakr al- Baghdadi. Image from video posted on a militant website, AP Images.

ISIS is led by Abu Bakr al Baghdadi, who has been active in jihadist groups since the 1990s. Baghdadi was born in Samarra in 1971. He reportedly received jihadist training in Afghanistan in the late 1990s, when he lived with Abu Musab al Zarqawi in Kabul. He fought with jihadists in Fallujah in the early 2000s after returning to Iraq, and was reportedly held at the U.S. detention facility Camp Bucca from February to December 2004. In 2010 he assumed leadership of ISIS, then called the Islamic State of Iraq. When the group renamed itself the Islamic State in 2014, Baghdadi took the title of caliph. In theory, he has total authority within ISIS territory, but his day-to-day responsibilities are unclear. 

Jihadist publications claim that Baghdadi is from a religious family descended from noble tribes, and that he holds a PhD from Baghdad’s Islamic University. Baghdadi is known for avoiding the spotlight. There are few known photos of him, and he reportedly conceals his identity with a bandanna from everyone outside his small inner circle.  

Leadership Selection and Qualifications

ISIS publications have emphasized Baghdadi's scholarship and piety. The following quotes illustrate ISIS's views on the leader's qualifications and authority.

“The scholar who practices what he preaches, the worshipper, the leader, the warrior, the reviver, descendent from the family of the Prophet, the slave of Allah, Ibrāhīm Ibn‘Awwād IbnIbrāhīm Ibn‘AlīIbnMuhammad al-Badrīal-Hāshimīal-Husaynīal-Qurashīby lineage, as-Sāmurrā’ī by birth and upbringing, al-Baghdādī by residence and scholarship. And he has accepted the bay’ah (pledge of allegiance). Thus, he is the imam and khalīfahfor the Muslims everywhere.” - This is the Promise of Allah 

“Imamah (leadership) in religious affairs cannot be properly established unless the people of truth first achieve comprehensive political imamah over the lands and the people.” - Issue #1 of ISIS's "Dabiq" magazine 

“We will continue to obey the imam as long as he orders us to obey Ar-Rahman (the Most Merciful). But if he orders us to disobey Allah, then we won’t obey those orders.”- Issue #1 of ISIS's "Dabiq" magazine 

Baghdadi's Worldview

On democracy : “The Muslims today have a loud, thundering statement, and possess heavy boots. They have a statement that will cause the world to hear and understand the meaning of terrorism, and boots that will trample the idol of nationalism, destroy the idol of democracy and uncover its deviant nature.”- July 1, 2014, in a speech 

On Iran: "Muslims' rights are forcibly seized in...Iran (by the rafidah)." ("Rafidah" is a pejorative term for Shiites) - July 1, 2014, in a speech 

On terrorism: "Terrorism is to worship Allah as He ordered you. Terrorism is to refuse humiliation, subjugation, and subordination (to the kuffar– infidels). Terrorism is for the Muslim to live as a Muslim, honorably with might and freedom. Terrorism is to insist upon your rights and not give them up...Terrorism does not include the extreme torture and degradation of Muslims in East Turkistan and Iran (by the rafidah), as well as preventing them from receiving their most basic rights." 

On the United States and Israel: “O ummah of Islam, indeed the world today has been divided into two camps and two trenches, with no third camp present: The camp of Islam and faith, and the camp of kufr (disbelief) and hypocrisy – the camp of the Muslims and the mujahidin everywhere, and the camp of the Jews, the crusaders, their allies, and with them the rest of the nations andreligions of kufr, all being led by America and Russia, and being mobilized by the Jews.” - July 1, 2014, in a speech


Baghdadi is the supreme political and religious leader in ISIS territory. The caliph has virtually unchecked authority, but in practice he relies on deputies to manage administration of its territory. The Islamic State has a Shura Council that can theoretically depose the caliph, but all members are appointed by Baghdadi. The upper echelon of ISIS leadership includes Baghdadi’s advisers, as well as councils responsible for security, military affairs, media, and finance.

ISIS leadership has direct command and control over its fighters in Iraq and Syria, though its ability to direct its affiliates abroad is unclear. In March 2015, ISIS affiliates claimed responsibility for the Bardo Museum attacks in Tunis and the mosque attacks in Yemen, but U.S. officials were skeptical of the extent to which the attacks were coordinated by ISIS leadership in Iraq and Syria. 

ISIS members have tended to be younger than those in al Qaeda. Recruitment efforts have targeted young Muslims between the ages of 18 and 35. ISIS has used social media platforms, including Twitter, Facebook, Instagram, and other programs that typically reach a younger audience. By March 2015, there were at least 46,000 pro-ISIS Twitter accounts, according to the Brookings Institution.

Other key figures

  • Abu Muslim al Turkemani, also known as Fadhil Ahmad al-Hayali Baghdadi’s deputy who oversaw operations in Iraq. He was reportedly killed by a U.S. strike in 2014.
  • Abu Ali al Anbari, Baghdadi’s deputy who oversees operations in Syria.
  • Abu Mohammed al-Adnani, official spokesman for ISIS.
  • Abu Arkan al Ameri, head of ISIS’s 10-member shura council.
  • Abd al-Rahman Mustafa al Qaduli, a senior leader and former deputy of Zarqawi in al Qaeda in Iraq. 
  • Tarkhan Tayumurazovich Batirashvili, a senior commander based in Syria and member of the shura council.

Laws and Courts

ISIS has no rule of law or due process by international standards. It carries out the most severe forms of punishment allowed under Islamic law, known as hudud. Common practices include flogging, stoning and amputation. It carries out executions, sometimes in public, by beheading, crucifixion and even burying or burning prisoners alive. It has engaged in mass executions, some broadcast on social media. It takes foreign hostages, particularly aid workers and foreign journalists.

ISIS began establishing courts in July 2013, and has since expanded its judicial system. The group’s bureaucracy also includes local police forces and religious police, known as al Hisba, who conduct regular patrols to crack down on religious offenses like insulting God or conducting business transactions during prayer time. As of July 2014, there were more than a dozen Hisba offices in Raqqa and Aleppo that had logged hundreds of violations.

While the total number of ISIS executions has not been verified, A U.N. report estimates that ISIS militants killed 8,493 civilians in Iraq alone in 2014. The group claimed to have executed 1,700 Shiites in a single incident, after seizing a prison outside Mosul in June.

In their own words

“[Courts] govern by the laws of God, implement the hudud punishments, ensure rights, and extend justice; dozens of cases are dealt with daily, and it is based upon a legal and administrative cadre” - ISIS report on the Aleppo province (translation viaInstitute for the Study of War)

“We treat people by what is shown to us by their actions and their devotion to Islam. Our actions are based on unequivocal evidence and not based on supposition and questionable premises.” - From an ISIS city charter

“Individuals under our rule are safe and are supported under Islamic law, where their individual rights are preserved and justice is served to protect the oppressed.” - From an ISIS city charter


The Islamic State has forced females back behind the veil and actively discouraged them from education, work and even appearing in public. It actively recruits women to move to the territories of Iraq and Syria it now controls. Ten percent of its Western recruits are reportedly female. Jihadist social media portray the Islamic State as an idyllic Islamic society and an alternative to life in the West. But media accounts and testimony of women who have escaped indicate women experience violence, rape, forced marriage, and general repression.

In ISIS territory, women’s freedoms are severely curtailed. They are encouraged to stay at home and are required to have a male escort to go out in public. In Raqqa, for example, women have reportedly been beaten or arrested for traveling outside their homes without a male chaperone. ISIS requires that women over the age of ten veil from head to toe when leaving the house. A November 2014 UN report said police regularly evaluate women’s clothing at multiple checkpoints in ISIS-held towns. ISIS also inflicts harsh punishments on women who do not comply with dress requirements. ISIS documents do not detail punishments, but a woman in Mosul was reportedly sentenced to 40 lashes for violating the dress code. Men are also punished if ISIS determines that a woman within their family is not dressed properly.

Many young Syrian women in ISIS territories have also reportedly been forced to marry against their will. ISIS opened “marriage bureaus” to facilitate marriages between women and ISIS fighters. Militants have financial incentives to wed, as married fighters receive a $1,200 grant, a home, and fuel for heating. Many women have been victims of violence and assault, and militants have executed women for adultery. ISIS stoned eight women to death in Raqqa alone in June 2014. After seizing Mosul in June 2014, ISIS militants reportedly went door-to-door assaulting women. The UN estimated in 2014 that ISIS forced 1,500 women, girls, and young boys into sexual slavery.

ISIS provides limited educational opportunities for young girls. It has established female-only religious schools, which teach students to memorize the Quran. ISIS enforces gender segregation in these schools, and prohibits male teachers from teaching girls.

ISIS is also unusual among jihadist groups in that it has an all-female morality police. The al Khansaa Brigade in Raqqa arrests and punishes other women for not abiding by ISIS’s strict rules on women’s behavior in society. Members of the brigade reportedly ask women questions to test their knowledge of prayer, fasting, and the hijab. In January 2015, the brigade released a semi-official manifesto on the role of women in society. It encouraged women to stay at home and detailed three limited circumstances in which it was permissible for women to leave the house: jihad, studying the Quran, and serving as a doctor or teacher.

In their own words

“Stability is in the house, inherently the khidr,or women’s quarters, and go out [from the house] only when necessary for the guidance of the mothers of the believers… blessings upon them.”- From an ISIS city charter

"Woman was created to populate the Earth just as man was. But, as God wanted it to be, she was made from Adam and for Adam. Beyond this, her creator ruled that there was no responsibility greater for her than that of being a wife to her husband." - From a manifesto on women released by the al Khansaa Brigade, translation via the Quilliam Foundation

“To the honorable women: God is in decency and loose jackets and robes.” - From an ISIS city charter

“Women…are completely forbidden from showing their eyes [and wearing] open abayas that reveal colorful clothes worn underneath.”

“[Clothing] must not be decorated with beads, sequins, or anything else.”

“[Women] must not wear high heels.”

“Anyone who violates this will be penalized.”

- ISIS statement distributed in Deir Ezzor (translation via the Syrian Observatory for Human Rights)


ISIS has little tolerance for religious minorities. It has tried to cleanse its territory of people it deems unbelievers, including Shiites and non-Muslims. It has reportedly killed hundreds of Shiites and Yazidis, among others. 

ISIS does not permit Christians to build new churches or display religious symbols in public places. There have also been reports of Christians being forced to convert to Islam or face execution. In Iraq, ISIS has destroyed Christian property and churches.

ISIS deals with other religious minorities even more harshly. Militants invaded Yazidi communities in Sinjar in August 2014, killing those who refused to convert, and driving tens of thousands from their homes. ISIS has also killed Shiites in newly captured territories. One ISIS member stated that the Islamic State’s territorial gains in 2014 “purged vast areas in Iraq and Syria from the filth of the Safavids,” referring to the sixteenth century Persian Shiite dynasty. ISIS is also widely reported to kidnap, sell and rape women and children who are deemed unbelievers, most notably Yazidis. In late 2014, ISIS released a pamphlet attempting to justify the kidnapping, enslavement, and rape of non-Muslim women and children.

ISIS's sectarian focus dates back to the early 2000s. Under the leadership of Abu Musab al Zarqawi, ISIS – then known as Al Qaeda in Iraq – attacked Shiites and even fellow Sunnis who did not share the group's worldview. Al Qaeda leaders feared that mass sectarian killings and excessive brutality detract from its goal of attacking the West and alienate potential followers. In 2005, al Qaeda leaders warned Abu Musab al Zarqawi against carrying out sectarian attacks that could provoke a backlash among fellow Sunnis.

The March 2015 attacks on two Shiite mosques in Yemen reflected the contrast between al Qaeda and ISIS. Sanaa Province, an ISIS affiliate, claimed responsibility for the attacks. Al Qaeda in the Arabian Peninsula, al Qaeda’s Yemeni affiliate, denied involvement, reaffirming commitment to al Qaeda leader Ayman al Zawahiri’s guidelines to avoid attacks on mosques and other areas that target Muslims. 

In their own words

“Their creed [of Yazidis] is so deviant from the truth that even cross-worshipping Christians for ages considered them devil worshippers and Satanists.”- Issue # 4 of ISIS's “Dabiq” magazineOctober 2014

“Be very wary of allying with the Jews and Christians, and whoever has slipped by a word, then let him fear Allah, renew his faith, and repent from his deed. […] Even if he supported them just by a single word. He who aligns with them by a single word falls into apostasy– extreme apostasy.” - Issue # 4 of ISIS's "Dabiq" magazine

“Unlike the Jews and Christians, there was no room for jizyah payment. Also, their women could be enslaved unlike female apostates who the majority of the fuqahā’ say cannot be enslaved and can only be given an ultimatum to repent or face the sword. After capture, the Yazidi women and children were then divided according to the Sharī’ah amongst the fighters of the Islamic State who participated in the Sinjar operations.”  - Issue # 4 of ISIS's "Dabiq" magazine

"By using methods that led to maximum chaos and targeting apostates of all different backgrounds, the mujahidin were able to keep Iraq in constant instability and war, never allowing any apostate group to enjoy a moment of security.” - Issue #1 of ISIS's "Dabiq" magazine, July 2014

The West

ISIS has a strongly anti-Western worldview. Baghdadi has urged Muslims around the world to rise up and avenge injustices inflicted by the West. ISIS has publicly beheaded Western hostages. 

Most of its victims have been local, and it has carried out mass killings of minorities in its territory. But in 2015, ISIS and its affiliates claimed responsibility for high-profile attacks on Western targets. They included the bombing of a Russian airliner, which killed all 224 people on board, and a series of coordinated attacks in Paris that killed more than 120.

In their own words

“Be very wary of allying with the Jews and Christians, and whoever has slipped by a word, then let him fear Allah, renew his faith, and repent from his deed. […] Even if he supported them just by a single word. He who aligns with them by a single word falls into apostasy– extreme apostasy.” - Issue # 4 of ISIS's “Dabiq” magazine, October 2014

“The world today has been divided into two camps and two trenches, with no third camp present: The camp of Islam and faith, and the camp of kufr (disbelief) and hypocrisy – the camp of the Muslims and the mujahidin everywhere, and the camp of the Jews, the crusaders, their allies, and with them the rest of the nations and religions of kufr, all being led by America and Russia, and being mobilized by the Jews.”  - July 1, 2014, in aspeech by Baghdadi

“[American hostage Steven Sotloff’s] killing was the consequence of US arrogance and transgression which all US citizens are responsible for as they are represented by the government they have elected, approved of, and supported, through votes, polls, and taxes.”- Issue #4 of ISIS's "Dabiq" magazine, October 2014

Click here for a complete chronology of ISIS since 2004.

About the Author

Cameron Glenn

Senior Program Assistant, Iran & Middle East Programs, U.S. Institute of Peace
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